The purpose of this study is to determine the effect of Azopt (brinzolamide) and Trusopt (dorzolamide) on the rate of aqueous humor production in normal human eyes. Azopt is a new eyedrop used to treat glaucoma. Azopt and Trusopt have been tested in human eyes and have been approved for human use by the FDA. Both are considered to be safe. A condition like conjunctivitis is the primary side effect reported in clinical studies, and this reaction resolves when the drug is stopped. As with all eye medication, irritation and allergic reactions can occur. The two drugs were found to be equivalent in efficacy in human subjects.